1. Field of the Invention
This invention relates to lids for covering containers for liquids, such as glasses and cups, and, more particularly, to a lid for preventing accidental spillage of the liquid within the container while allowing a person to drink the liquid from the container without removal of the lid.
2. Description of the Related Art
When liquids, such as milk, juice, coffee, tea, soda pop, and the like, are carried in cups or glasses in moving vehicles, such as airplanes, trains, buses, or cars, the irregular movement of the vehicle often causes the liquid to splash within the container. Also, sudden or abrupt movements can cause the container to be tipped over or dropped. When children are learning to use cups for drinking they do not always set the cup down in the upright position. Children experimenting with a new situation will try to splash the liquid inside the container or will set the container down in a totally inverted position. All of these situations can lead to the liquid spilling, thus causing staining of fabrics, or skin burns from hot liquids.
Many attempts have been made to provide a container and cover for preventing the splashing, the spilling of liquids for use in moving vehicles. However, such attempts have resulted in cups, containers, and covers that are expensive to produce, difficult and cumbersome to use, and typically provide that the container and cup be made to accommodate one another, so that a universal lid for use in many different types of containers has not been produced.
An example of a container lid that attempts to solve these problems is shown in U.S. Pat. No. 4,915,250 issued Apr. 10, 1990 to George W. Hayes, Jr. The Hayes lid addresses the problem of splashing and tipping with the lid in a tilted or sideways position. However, the Hayes lid does not completely solve the problem of leakage when the lid is placed in a completely inverted position. Specifically, the Hayes reference discloses in column 3, lines 1-3 relenting to when the cup is in the inverted position "the liquid will still not exit the container, since the vent will also be blocked by liquid and atmospheric pressure will keep the liquid locked in the container." Also, the Hayes reference discloses in column 6, lines 18-21 that "any shape can be used as long as the chamber extends from one edge of the lid, across the lid, and back again to achieve the spill-proof characteristics." This teaching has disadvantages in that atmospheric pressure alone will not keep the liquid from spilling in all likely encountered circumstances. Constant removal and replacement of the lid will result in wear which can allow leakage air, thereby over time equalizing the pressure and causing the liquid to leak. When the liquid is a carbonated or hot, the pressure created can overcome the atmospheric pressure, thereby permitting leakage.
It is, therefore, an object of the present invention to provide an improved lid for a container to prevent spilling of liquid from the container when the container is in a horizontal or even inverted position and to prevent splashing of the liquid from the container when the container is in a vertical position.
Another object of the invention is to provide such a lid that is able to be used with standard containers and does not need a customized container to be adapted to it.
Another object of the invention is to provide such a lid that is relatively simple and inexpensive to manufacture.